Size-Dependent Hydrogen Atom Attachment to Gas-Phase Hydrogen-Deficient Polypeptide Radical Cations
Size-Dependent Hydrogen Atom Attachment to Gas-Phase Hydrogen-Deficient Polypeptide Radical Cations
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DOI：
10.1021/jacs.7b10318
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发表时间：
2018-01-17
影响因子：
15
通讯作者：
Zubarev, Roman A.
中科院分区：
文献类型：
--
作者：
Di Stefano, Luciano H.;Papanastasiou, Dimitris;Zubarev, Roman A.
尽管对羰基氧有显著的亲和力，但热氢原子以非常低的速率附着到未修饰的多肽上，而氢-氢交换速率很高。在这里，使用新的omnitrap设置，我们发现，附着到多肽是更容易当自由基网站已经存在，但速率降低较大的自由基离子。可能的解释是在缺氢自由基中分子内氢原子重排到更稳定或更难接近的位置。
Despite significant affinity to carbonyl oxygens, thermal hydrogen atoms attach to unmodified polypeptides at a very low rate, while the hydrogen- hydrogen exchange rate is high. Here, using the novel omnitrap setup, we found that attachment to polypeptides is much more facile when radical site is already present, but the rate decreases for larger radical ions. The likely explanation is the intramolecular hydrogen atom rearrangement in hydrogen-deficient radicals to a more stable or less accessible site.